Long-term growth investing centers on picking high-quality companies with competitive advantages and large runways ahead, while not caring as much about today's P/E ratio.

That's because over the long term, high-quality stocks should win out. Even Warren Buffett's late business partner, Charlie Munger, once noted that a company's return on capital should reflect overall returns over a long-enough period, even if you pay a "fancy-looking price" in the present.

In that light, the following three growth companies look like solid long-term buys today, even after good runs off their April bottoms.

Amazon

Amazon (AMZN 0.61%) has been one of the best growth companies over the long term and should continue to be so in the future. Its e-commerce platform continues to deliver more daily essentials to more and more people even after 30 years, while its cloud computing platform, Amazon Web Services (AWS), has become a high-profit juggernaut, generating $112 billion in revenue over the past 12 months with a 37.5% operating margin.

This year should also see the launch of Project Kuiper, Amazon's satellite-based broadband company. Kuiper launched its first satellites into space back in April and aims for its first commercial revenue this year.

Artificial intelligence also has the prospect of greatly boosting Amazon's future profit. That should come in several forms: providing AI infrastructure on AWS, developing its own AI services on Amazon's proprietary Trainium chips, and applying AI to its existing e-commerce business. E-commerce retail is capital-intense and difficult, but AI has the prospect of turning Amazon's treasure trove of data into better customer targeting as well as more efficient fulfillment and delivery.

This month, CEO Andy Jassy wrote a letter to employees enumerating the myriad ways generative AI is making Amazon a better, more profitable company, although he also cautioned: "We will need fewer people doing some of the jobs that are being done today, and more people doing other types of jobs. ... It's hard to know exactly where this nets out over time, but in the next few years, we expect that this will reduce our total corporate workforce as we get efficiency gains from using AI extensively across the company."

While the announcement may be nerve-wracking to current Amazon employees, it seems to bode well for Amazon's profit potential, and therefore its shareholders.

Sea Limited

Another e-commerce company firing on all cylinders is Southeast Asian super-app Sea Limited (SE -5.92%). A former pandemic darling, Sea fell on hard times in 2022, falling by more than 90% at one point. And despite quintupling over the past year and a half, Sea's stock is still more than 50% below its former highs.

Today, Sea's businesses are back firing on all cylinders. Its cash cow mobile gaming business, underpinned by self-developed game Free Fire, seems to have just awakened last quarter from its long, post-pandemic slumber. The gaming unit, named Garena, saw gross bookings jump 43% in just a single quarter to $775 million, its biggest bookings figure since the second quarter of 2022 three years ago.

The post-pandemic period also forced management to get its loss-making units profitable quickly. These included Shopee, Sea's e-commerce platform that is now the largest in Southeast Asia, and SeaMoney (now called, "Monee"), its digital finance business.

Image source: Getty Images.

During the post-pandemic period of high interest rates, Sea slashed costs, focusing almost exclusively on its bottom line at the expense of growth, bringing these units to profitability on their own by the end of 2022.

Sea appears to have now found a happy medium of profitable growth, not only for its business as a whole, but also for each unit independently. Last quarter, overall revenue jumped nearly 30%, while adjusted EBITDA rocketed 135% higher.

With all units now profitable and growing, it's possible Sea may venture into other geographies and businesses. Sea has already expanded in Brazil, its only market outside Southeast Asia. But before the pandemic, management had discussed expanding to Europe and India. Those plans were scuttled once inflation and interest rates picked up, but given the business' newfound financial strength, new expansion initiatives may be on the table once again.

SharkNinja

Finally, household cleaning, cooking, kitchen, and beauty products company SharkNinja (SN 0.27%) has been public for less than two years, but it's a strong growth brand to watch.

SharkNinja has its origins as a vacuum vendor in the 1990s under a different name, but it came to prominence after introducing the Shark premium vacuum cleaner in 2007 and then the Ninja brand of kitchenware in 2009. In 2017, the company took an investment from Hong Kong-based private equity firm CDH Investments under its investment holding company JS Global, and in 2023, it spun off SharkNinja onto the New York Stock Exchange without a traditional capital-raising IPO.

SharkNinja makes premium, highly engineered products that can generate five-star ratings, targeting customers looking for high-quality home products at a reasonable price. The mass-premium strategy has worked, with SharkNinja's revenue growing to $5.5 billion across 36 different household product sub-categories today. Revenue has compounded at a 21% annualized rate since 2008, with projected 12% growth in 2025. That's still really impressive, considering the company is now larger, making it harder to grow, while also under the cloud of tariffs. SharkNinja has also shown an ability to grow in a capital-efficient, profitable manner, with a return on equity of 25%.

SharkNinja aims to add two new subcategories per year, and it has ample room to expand geographically, having entered the U.K. in 2014 and Western Europe beginning in 2020. Given its strong track record of profitable growth and long runway ahead, SharkNinja is a solid buy today at just under 20 times this year's earnings estimates.